Method and apparatus for operating a starter for an internal combustion engine
First Claim
1. A method for controlling a starter that is disposed on an internal combustion engine, the starter including a multi-phase electric motor, a controller and an inverter, the method comprising:
- determining initial current commands for operating the electric motor in response to an activation command, wherein the activation command includes a rotational speed command concurrent with a motor torque command;
determining electrical current transferred from a DC power source to the electric motor and a rotational position of an output member of the electric motor, wherein the electrical current is determined directly without an intervening current prediction step;
determining feedback currents from the electric motor based upon the electrical current transferred to the electric motor and the rotational position;
determining interim voltage commands based upon the initial current commands and the feedback currents;
subjecting the interim voltage commands to voltage limits to determine final voltage commands;
determining a position compensation term based upon the rotational position and a rotational speed of the electric motor; and
controlling, via the controller, operation of the inverter in a pulse width-modulated mode to control the electric motor based upon the final voltage commands and the position compensation term.
1 Assignment
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Accused Products
Abstract
A starter for an internal combustion engine includes a multi-phase brushless electric motor, a controller and an inverter. A method for controlling the starter includes determining initial current commands for operating the electric motor in response to an activation command. Electrical current supplied to the electric motor and a rotational position of an output member of the electric motor are monitored. The electrical current is monitored directly without an intervening current prediction step. Interim voltage commands are determined based upon the initial current commands and the monitored currents, and final voltage commands are determined by subjecting the interim voltage commands to voltage limits. A rotational position compensation term is determined based upon the rotational position and rotational speed of the electric motor, and operation of the inverter is controlled to control the electric motor based upon the final voltage commands and the rotational position compensation term.
38 Citations
16 Claims
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1. A method for controlling a starter that is disposed on an internal combustion engine, the starter including a multi-phase electric motor, a controller and an inverter, the method comprising:
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determining initial current commands for operating the electric motor in response to an activation command, wherein the activation command includes a rotational speed command concurrent with a motor torque command; determining electrical current transferred from a DC power source to the electric motor and a rotational position of an output member of the electric motor, wherein the electrical current is determined directly without an intervening current prediction step; determining feedback currents from the electric motor based upon the electrical current transferred to the electric motor and the rotational position; determining interim voltage commands based upon the initial current commands and the feedback currents; subjecting the interim voltage commands to voltage limits to determine final voltage commands; determining a position compensation term based upon the rotational position and a rotational speed of the electric motor; and controlling, via the controller, operation of the inverter in a pulse width-modulated mode to control the electric motor based upon the final voltage commands and the position compensation term. - View Dependent Claims (2, 3, 4, 5, 6, 14)
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7. A method for controlling a starter that is disposed on an internal combustion engine, the starter including a multi-phase brushless electric motor coupled to a rotatable pinion gear, a controller and an inverter, the method comprising:
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determining initial current commands for operating the electric motor in response to an activation command, wherein the activation command includes a rotational speed command concurrent with a motor torque command; monitoring, via current sensors, electrical current transferred from a DC power source to the electric motor, wherein the electrical current is monitored directly without an intervening current prediction step; monitoring, via a rotational position sensor, a rotational position of the pinion gear; determining feedback currents from the electric motor based upon the electrical current transferred to the electric motor and the rotational position of the pinion gear; determining interim voltage commands based upon the initial current commands and the feedback currents, including employing a proportional/integrator control routine to determine the interim voltage commands, wherein the integrator is subjected to a dynamic integrator clamping element and an anti-windup element from a gain saturation limiter; subjecting the interim voltage commands to voltage limits to determine final voltage commands; determining a rotational position compensation term based upon the rotational position of the pinion gear and a rotational speed of the electric motor; determining pulse width-modulated commands for controlling the inverter based upon the final voltage commands and the rotational position compensation term; and controlling, via the controller, operation of the inverter to control the electric motor based upon the pulse width-modulated commands. - View Dependent Claims (8, 9, 10, 11, 15)
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12. A starter disposed on an internal combustion engine, comprising:
a multi-phase brushless electric motor coupled to a rotatable pinion gear, a controller, a DC power source, and an inverter, the controller operatively connected to the inverter, the controller including an instruction set, the instruction set executable to; determine initial current commands to operate the electric motor in response to an activation command, wherein the activation command includes a rotational speed command concurrent with a motor torque command; monitor electrical current transferred to the electric motor from the DC power source, and a rotational position of the pinion gear; determine feedback current commands for the electric motor based upon the electrical current transferred to the electric motor and the rotational position of the pinion gear; determine interim voltage commands based upon the initial current commands and the feedback currents, including employing a proportional/integrator control routine to determine the interim voltage commands, wherein the integrator is subjected to a dynamic integrator clamping element and an anti-windup element from a gain saturation limiter; subject the interim voltage commands to voltage limits to determine final voltage commands; determine a rotational position compensation term based upon the rotational position of the pinion gear and a rotational speed of the electric motor; and control operation of the inverter in a pulse width-modulated mode to control the electric motor based upon the final voltage commands and the rotational position compensation term. - View Dependent Claims (13, 16)
Specification